This invention relates to a molding device and more particularly to a hydraulic impact molding device of the type wherein instantaneously high hydraulic pressure is generated for molding a metal workpiece or like workpiece.
Conventional hydraulic pressure molding devices are generally unsatisfactory because the wall thickness of the formed article is thinner than that of the workpiece to be deformed. As the workpiece is deformed to the mold cavity, the wall thickness thereof narrows as the diameter of the deformed workpiece increases, and cracks and other defects frequently occur in the molded article.
According to the instant invention, a molding device is provided wherein changes in wall thickness of the workpiece during deformation thereof are minimized, thereby concomitantly minimizing the number of defective molded articles produced thereby.